A financial card affiliate registered with a settlement service provided by a bank or a credit card company may have a trade cost paid by a customer using a financial card, such as a cash card or credit card provided by the customer. A POS terminal is widely used in the financial service field using the credit card of a customer. A customer who visits a store can pay a price through his or her financial card using a POS terminal provided in the store.
In the financial settlement service using the POS terminal, however, an accident that personal information about a user illegally leaks is generated due to the hacking of card information. In order to solve such a security problem, Korean Patent No. 10-1616842 (POS Payment Processing System Enhanced Security and Method For Processing Payment Thereof) discloses a POS payment processing system having enhanced security although card information is exposed by decoding encrypted code data using a decryption key, but still has a possibility of a security accident if a pseudo random number is used.